What effect does dehydration have on urine concentration?

Dehydration leads to concentrated urine because the body attempts to conserve water during times of reduced fluid intake. When there is insufficient water, the kidneys respond by reabsorbing more water back into the bloodstream, resulting in less water being excreted in the urine. This process increases the concentration of solutes, including electrolytes and waste products, in the urine.

Additionally, the hormone vasopressin (antidiuretic hormone or ADH) is released in response to dehydration, promoting further water reabsorption in the kidneys. This hormonal regulation plays a crucial role in maintaining the body’s fluid balance and ensuring that essential functions continue despite reduced hydration levels. As a result, the urine becomes more concentrated, showcasing a higher specific gravity and darker color, indicating a higher concentration of solutes.